Slab casting apparatus

ABSTRACT

Apparatus for casting in succession a plurality of metal slabs of fixed length wherein there is a single open-ended casting mold and a number of supporting units of the type having opposed panels in which the cast slabs are cooled. The opposed panels of each supporting unit are reciprocated up and down during the casting in such manner that one moves up as the other moves down, and are similarly reciprocated to facilitate removal of the casting from the supporting unit. The supports are each suspended from a carriage in such manner that when one slab has been cast, it may be moved away and another brought beneath the mold, or the mold moved to position over another supporting unit.

United States Patent Bungeroth et a1.

[72] Inventor Erik Allan Olsson 2,895,190 7/1959 164/282 Zurich, Switzerland 3,167,829 2/1965 Hess et a1 164/282 [21] Appl. No. 809,233 3,384,939 5/1968 Baker 25/2 [22] Filed Mar. 21, 1969 3,480,074 1 1/1969 Bykov et a1. 164/282 [45] Patented Nov. 16, 1971 FOREIGN PATENTS [731 Assgme gm' gfifi 161,606 311955 Australia 164/282 Primary Examiner--Robert D. Baldwin Anorney-Parmelee, Utzler & Welsh [54] SLAB CASTING APPARATUS 14 Claims, 15 Drawing Figs.

ABSTRACT: Apparatus for castmg 1n successlon a plura11ty of U.S. t l lab f fixed length wherein there is a single open. 164/282, 164/283, 164/412 ended casting mold and a number of supporting units of the [51 Int. Cl 9/00, t havin o ed anel in which the cast slabs are cooled 322d 11/08 The opposed panels of each supporting unit are reciprocated 0f up a d down during the casting in uch manner that one 1301 274 moves up as the other moves down, and are similarly reciprocated to facilitate removal of the casting from the sup- [56] References Cited porting unit. The supports are each suspended from a carriage UNITED STATES PATENTS in such manner that when one slab has been cast, it may be 3,433,286 3/1969 Jensen et a1. 164/274 moved away and another brought beneath the mold, or the 1,206,150 1 1/1916 Slick 164/406 X mold moved to position over another supporting unit.

TJH' PATENTEUuuv 16 I97! 3, 620,285

sum 1 OF 7 INVENTOR ERIK ALLAN OLSSO/V his Attorney PATENTEDuuv 1s nan SHEET 3 OF 7 INVENTOR ERIK ALLAN 01.8.90

his A Hornay PATENTEU U 16 I97! 3.620.285

his Home PATENTEnunv 16 I97] 3,620,285

sum 5 [IF 7 N INVENTOR ERIK ALLAN OLSSON By/ZMQ w his Attorney PATENTEDNUv 1s nan 3.620.285

sum 8 or 7 LEI lu's Attorney SLAB CASTING APPARATUS This invention relates to the casting of metal into slabs or other bodies of fixed length through the use of an open-ended mold such as a mold used in continuous casting, and is for an apparatus especially useful for casting a succession of slabs or large bodies with the use of one mold with a plurality of separate supporting units into which the castings are successively received as they emerge from the mold and retaining them until they have solidified sufficiently to be self-sustaining. The invention may be regarded as a semicontinuous casting apparatus and is especially applicable to the casting of large metal slabs.

Large slabs are generally cast in ingot molds in which the molten metal is poured and solidifies and cools, but the size of the molds imposes practical limits on the size of the slabs, and there are other drawbacks to the use of fixed molds in forming large bodies of metal. On the other hand, continuous casting presents many difficulties with large slabs, due to the fact that where the slab is wide relative to its thickness, it is difficult to support the thin walls of the casting against the hydrostatic pressure of the molten metal inside the casting for the required length of time and gives rise also to other obstacles, including excessive building heights.

The present invention provides a practical solution using an open-ended mold of the type used in continuous casting and two or more supporting units of fixed length so arranged that the casting which emerges from the mold with a thin skin or shell is adequately supported and retained in the support until it has cooled to a level where it may be removed while one or more similar supporting units are used to support a succeeding casting or successive castings. With several supporting unitsa succession of slabs may be cast with little loss of time and without the problems incident to the use of individual ingot molds. Also, the obstacles encountered in continuous casting operations where the casting must be cut into lengths and cutting can only be done at a place where the molten metal has completely solidified are avoided, and excessively high structures are not necessary.

In an application for US. Pat. Ser. No. 802,478, Open- Ended Mold Casting Apparatus and Method, filed by Hans Bieri on Feb. 26, I969, and assigned to my assignee, there is disclosed a supporting apparatus for use with an open-ended mold wherein the casting as it emerges is engaged between two panels that are reciprocated in opposite directions or otherwise moved in such manner that one has a downward component of movement as the other one has at least some of the time an upward component. This has the effect of substantially neutralizing the friction between the panels and the casting so that the casting advances between the panels in increments under the influence of gravity, or under the tension under which the casting is pulled away from the mold by pinch rolls, or both. The speed and manner of reciprocation of the panels and the inertia of the casting gives the casting a substantially uniform rate of descent for all practical purposes. The panels have a series of closely spaced bars therein extending in the direction of travel of the casting which are the members that actually bear against and support the casting while water is sprayed between the bars onto the surface of the casting. These bars give continuous longitudinal support to the casting for the full length of the panels, so that even very wide castings, such as slabs, may be supported against bulging or breakouts due to the hydrostatic pressure of the molten metal inside the initially frail skin of the casting.

The present invention makes use of two or more supporting units of this kind in which the lengths of the panels are only slightly greater than the lengths of the slabs to be cast. When a casting operation is stopped with one unit, another unit is placed under the mold and a second casting is run into it. The casting is again stopped when the second unit has received a sufficient length of metal and the operation repeated in a third unit, etc., and as each unit is filled in this manner, the metal is allowed to cool. By the time the last unit has received a casting, the metal in the first will have solidified sufficiently for the casting to be removed. and the casting is removed from it and it is then moved into position under the mold to again receive another casting from the mold. This cycle may be carried on continuously for as long as necessary.

The usual procedure of moving a dummy bar up through the casting supporting unit, as is necessary with each fresh start of a continuous casting operation, is made unnecessary with the present invention where a dummy block is provided with each unit that is inserted into the top of each unit before it is brought into position under the ladle and relative vertical movement is effected between the dummy block and the mold to enter the dummy block into the bottom of the mold.

, The invention may be more fully understood by reference to the accompanying drawings wherein:

FIGII is a side elevation of a single support unit for a slab casting with parts broken away to show internal details;

FIG. 2 is a front elevation of the unit shown in FIG. 1;

FIG. 3 is a top plan view of the apparatus shown in FIG. 1;

FIG. 4 is a perspective view in vertical section of a dummy block for use with the apparatus shown in FIG. 1;

FIG. 5 is a somewhat schematic top plan view of a complete casting apparatus utilizing the units shown in FIGS. 1 to 4;

FIG. 6 is a longitudinal section in the plane of line Vl-VI of FIG. 7;

FIG. 7 is a transverse vertical section in the plane of line VII-VII of FIG. 6;

FIG. 8 is a diagrammatic side elevation on a small scale of a modified plant using but a single track;

FIG. 9 is a similar view of another modification showing fixed supports and a movable casting unit;

FIG. 10 is a perspective view in vertical section of a modified dummy block;

FIG. 1 1 is a schematic vertical sectional view through an arrangement for varying the amount of water supplied to different areas of the casting;

FIG. 12 is a transverse section in the plane of line XII-XII of FIG. I 1;

FIG. 13 is a fragmentary view of another form of dummy block showing it in position in the mold;

FIG. 14 is a perspective view of a portion of the dummy block shown in FIG. 13; and

FIG. 15 is a fragmentary transverse sectional view similar to FIG. 13 showing another form of dummy block and head therefor.

In the drawings, corresponding reference numerals indicate corresponding parts throughout.

Referring first to FIGS. 1 to 3 inclusive, there is shown a single supporting unit A of a type disclosed in said Bieri applica tion adapted to use with the present invention. In general it comprises a generally rectangular frame 2 having two wheels 3 at each side thereof near the four comers of the frame. These are adapted to roll on two elevated rails. The frame has side members 4 connected by cross members 5. Each of the side members 4 provides a support for a stub shaft 6, these stub shafts on the opposite sides of the frame being in transverse alignment.

There is a rocker arm 7 mounted on each stub shaft for limited oscillatory movement in a vertical plane. Equally spaced from the centers of the shafis 6 on each rocker arm are depending links 8. One pair of transversely opposite links 8 are pivotally attached at 9 to one of two panels 10, and the other two links 8' are pivotally attached at 9' to a second similar panel 10, the panels 10 and 10 being of similar construction and confronting each other in spaced relation, the space between them corresponding to the thickness of the slab S (FIG. 3) to be cast. The width of the panels exceeds the width of the slab.

As viewed in FIG. I, each rocker arm 7 haS an extension 7a extending toward the right. This arm has its outer end pivotally connected to the depending end of a link 11 having a yoke at its upper end fitted about an eccentric 12 so that the eccentric rotates the links 11 up and down, rocking the rocker bars 7 up and down, thereby simultaneously moving the panels up and down in equal but opposite directions, one panel moving up as the other moves down. The eccentrics 12 at each side of the frame are driven in unison from a single motor 13 supported on a bracket 14 on the right cm member 5. This motor drives a reduction gear, indicated at 15 which drives oppositely extending flexible drive shafi 16, the eccentrics being on the outer ends of these shafts. The maximum up and down travel of the panels 10 and 10 need be only a few millimeters to accomplish their purpose.

The panels 10 and 10' each have vertical side frame members at each side and the two panels are held apart by springs 21 located between the side frame members and confined against spreading too far by flexible tie rod assemblies 22 attached to the side frame members 20. Between the side frame members 20 there are a series of spaced rigid vertical bars 23 that form the working surfaces of the panels, these being the members that bear against and support the casting. There are vertically extending water pipes 24 staggered with respect to the bars 23 arranged to spray water through the spaces between the bars against the surface of the casting as it moves down between the panels and while it is cooling.

In FIG. 4 l have shown one form of dummy block or starter block to be used in starting the casting of each slab. It comprises a solid block 30 of metal corresponding in horizontal section to the shape of the slab S (FIG. 3) and the top has a ridge 31 across the top with an undercut stop 32 between the high and low areas of the top. The undercut is to interlock with the casting when the top of the block is projected into the open bottom of the mold and the molten metal solidifies in contact with it, as is well understood in the art.

Instead of the dummy block being formed in the manner above described, the form shown in FIG. 10 may be used. It is comprised of two parts 300 and b, with compression springs 30c tending to urge them apart, and tie rods 30d to limit the maximum spread between them. Part 300 has a top 31a that is if the size and shape of the slab, being shaped to have a close sliding fit in the casting mold. There is a ridge 32a formed in the same manner as the ridge of the block shown in FIG. 4. The advantage of this block is that it will make firmer frictional contact with the bars of the panels than a block of fixed size.

The invention of this application contemplates the use of at least two, and preferably several of these supporting units so arranged that they may be used in succession so that as casting is taking place in one, cooling may take place in another or others, while stripping of another is taking place and still another is being prepared with a dummy block to receive a coating. FIGS. 5 to 7 show a preferred arrangement for a large-scale operation, while FIGS. 8 and 9 show other arrangements. The plant here shown in FIGS. 5 to 7 comprises a structure which, as seen in plan (FIG. 5) is of a generally rectangular form in which there are three parallel sets of two-spaced rails forming tacks extending lengthwise of the structure, the rails of the first track being designated 40, those of the second track 41, and of the third track 42. There are also tracks comprised of two-spaced rails 43 across one end of the structure and a similar track comprised of rails 44 at the other end of the structure.

The structure itself is comprised of many vertical columns 45 and horizontal beams 46, some of which support the rails above described. As shown in FIGS. 6 and 7, the lengthwise extending rails 40, 41 and 42 are at a level below the cross rails 43 and 44. The wheels 3 of the casting supporting units A roll only on the lengthwise extending rails 40, 41 and 42. It will be seen that in FIGS. 5 to 7 the long dimension of the panels is parallel with the rails 40, instead of crosswise as in FIGS. 1 to 3. This is to illustrate that they may be arranged either way, and also to indicate a modified cooling arrangement to be hereinafter described. On the cross rails 43 there is a transfer car, designated generally as 48, and on the cross rails 44, there is a similar transfer car 48'. Since both transfer cars are of like construction, the same reference numerals designate corresponding parts of each.

Each transfer car has an approximately open square top frame 50 (see FIG. 5) with wheels 51 adjacent each comer that roll on the rails 43 or 44 as the case may be. From the top frame there is a depending structure 52 extending parallel to the rails 40, 41 and 42, and each of these supports a rail 53. As seen in FIG. 5, the rails 53 are in the same horizontal plane as rails 40, and when the transfer car is in this comer of the frame, these rails 53 align with the two rails 40. With this arrangement a casting supporting unit A on the rails 40 may be rolled from the rails 40 onto the matching rails 53 of the transfer car. The transfer car may then be moved on its rails crosswise of the frame until its rails 53 are aligned with rails 41 or 42, and the casting supporting unit may be rolled off the transfer car onto the selected track comprised of the two rails 42 or the two rails 43. In like manner the casting supporting unit may be moved from the track last selected onto the rails 53 of the transfer car 48' at the other end of the frame and moved to the lower left-hand comer as shown in FIG. 5 to be returned to the rails 40.

In this manner each of several supporting units A may be moved through a closed cycle around the frame. The casting unit to be described is located over the rails 40, so that the casting supporting units receive their castings in turn on the track 40 and then is moved in turn around the structure while the casting cools, is stripped from the support, receives a dummy block, and returns to position under the mold and ladle.

The casting ladle 60 is supported on a truck 61 on tracks 62 that extends crosswise of the rails 40 near one end of the apparatus. These tracks are at an elevation above the rails 40 a distance sufficient to allow the ladle to clear an open end mold located above one of the units A. The ladle is supported in a vertically adjustable frame 63 on the truck to permit it to be raised ad lowered a slight distance.

The mold, designated 64, is a conventional open-ended water-cooled mold of the type used in continuous casting operations. The long dimension of the rectangular mold opening, which conforms, of course, to the shape and dimension of the slab S, is parallel with the rails 40, and as shown in FIG. 6, its lower end just clears the top of one of the supporting units A. The mold itself is supported on the top beams of the frame structure at 65 (see FIG. 6).

With the procedure here contemplated, the usual tun-dish between the ladle and mold will be unnecessary, and that a valved pouring spout 66 of a type well-known in the industry on the bottom of the ladle will be submerged in the mold during the casting of a slab, but by elevating the frame 63, the ladle can be raised sufficiently for this spout to clear the mold when the ladle truck is moved from a position over the mold to a position at one side thereof, as necessary.

Below the tracks 62 are beams 67 for supporting an emergency ladle 68 into which the molten metal in the casting ladle 60 can be dumped if, during the casting operation, it is required that the casting of the metal be stopped for any reason.

In the operation of the apparatus the casting support units A always travel in a lengthwise direction as shown in FIG. 5 on their own wheels, but are always carried in a crosswise direction on a transfer truck. As viewed in FIG. 5, a starting position may be assumed to be the lower left-hand corner, where a supporting unit (not shown) would have been on the transfer car ready to be moved onto the rails 40. As indicated by the panel, marked dummy block setting," the shop crane lowers a dummy block into the top of a unit A and the panels are reciprocated to lower the dummy block until it is firmly held between the two panels, but below the level of the bottom of the mold.

From this position the supporting unit is rolled from the transfer car to a position under the mold. At this time the ladle car will have been moved to a position at one side of the rails 40. A crane hook is lowered through the mold, and since any object between the panels will travel or be walked" in the direction in which the part between the panels is urged, either by gravity or by pulling means, the panels are reciprocated while the crane lifts the dummy block, and it will be raised to close the bottom of the mold. The dummy block has tow parts urged away from each other by springs (P16. 1%) as previously described, so that it has good frictional contact with the panels.

The ladle is then raised by raising the frame 63 on the truck sufficiently for the discharge spout m to clear the top of the mold and the ladle is then moved to position over the mold and lowered so that the support projects into the mold, as a socalled submerged spout.

The valve (not shown) accessible from the top of the ladle as is customary with bottom pour ladies, is opened and the casting operation started. When the metal has reached a casting level in the mold, it will have solidified, as is usual, on the dummy block. The panels are then reciprocated and the dummy block, aided by the weight of the metal in the mold, will travel downward, with the casting, having a solidified exterior and a molten interior, progressively forming and pulling down with the dummy block. when the dummy block has moved down either to the bottom of the panels, or if a shorter slab is required, then to the desired level, the pouring is stopped. Actually the pouring should stop at a point that will permit all metal in the mold after the stopping to be utilized in the casting.

As the casting is pulled down into the supporting unit, it is sprayed with water and the spaced bars, while giving full support lengthwise of the casting against bulging under hydrostatic pressure of the metal inside the solidified shell of the casting, permits the rapid cooling of the slab. However, when the casting of the molten metal is complete, the slab will not have cooled internally to a condition where is is self-supporting. Therefore the unit is moved from under the mold, toward the right as viewed in FIG. 5, where the cooling may continue while another supporting unit A, similarly prepared with a dummy block, is brought into position and another slab is cast. in this way successive slabs are cast and moved aside for coolmg.

When a unit has come to the discharge end of the track provided by rails it), it is moved onto the transfer car 43. At this position the casting is ready to be stripped from the support. As shown in H6. 6 there may be a hydraulic ram structure 70 here shown with two pistons 71 operating through a roller conveyor table 72. They will initially exert an upward thrust on the dummy block while the panels are reciprocated to move the casting up to a level where its upper end may be engaged in a gripping device attached to the shop crane, and the casting, along with the dummy block walked" out of the supporting unit and the dummy block then detached. Altemately, the casting maybe lowered to just above the conveyor 72, the dummy block detached, and moved on the conveyor 72 to a receiving conveyor 73, to be there picked up by the crane and carried over to the dummy block setting" position for reuse, and the hydraulic ram arrangement then operated to raise the casting to a point where a crane tong or clamp can be attached to the top ofthe casting.

After the casting has been stripped from the supporting unit, the transfer car moves the unit to a position where the transfer car rails are in line with the rails 41 and the supporting unit is moved around to the dummy block setting position for a second similar cycle, while the transfer car 38 is returned immediately for the stripping of the slab from the next supporting unit. There are several of these units in use at one time, so that there is no holdup of operations to await a ready casting supporting unit. While the operation is semicontinuous, the casting of successive bodies, such as slabs, can be effected without requiring a casting plant of great height, while the metal cools, as would be necessary with straight continuous casting where the casting is cutoff into successive lengths. It thus eliminates very high buildings with heavy supports required to support the heavy loads as well as the hazards of working with molten metal at a considerable height where rupture of the casting could cause substantial damage. Also the problems of bending a heavy slab from a vertical path to a horizontal path in order to reduce the height as heretofore proposed is avoided.

In the usual practice of continuous casting, the casting is traveling continuously from the bottom of the mold support into the open air so that it is sprayed with water only during the period of travel from the mold through the supporting unit so that each length is uniformly subjected to the same cooling. With the present invention the casting comes to rest in the supporting unit, and if the spray were not varied, the lower end could be overcooled before the upper end had cooled adequately. To avoid this, it will be see that the pipes 24 are not vertically continuous, but that they are arranged in vertically distinct groups or banks with a header 240 at the bottom, and, incidentally, with the bars and tubes closer together at the top. As shown in FIGS. 11 and 12, these headers may be supplied with water from a vertical pipe 73 inside one of the side frame members 20 with ports 73:: opening into the headers Ma. A second pipe 74 rotatably or slidably fitted into pipe 73 has registering ports 74a that may be of downwardly decreasing diameter so that the supply of water to the lower headers is less. Also the supply to the lower ones can be cutoff or diminished by rotating or sliding the inner pipe vertically, moving the smaller lower ports out of register with the outer ports while lessening, but not cutting 03', the flow to the upper banks of tubes, so that the cooling can be controlled to more nearly approach the conditions of continuous casting.

Also, with the wide dimension of the panels parallel with the rails 50, fixed spray tubes may be provided on the supporting frame in addition to, or as a substitute for, the spray tubes 24 on the panels so as to direct water between the vertical bars of the panels. These may be arranged so that as the carriage moves slowly from the casting station to the transfer car 48, the area of the panels is exposed to fixed sprays that decrease from the top down, as indicated by the heavy dash line A-A where sprays are located on the frame in the area above this line, while the area below this line is clear of sprays. This again simulates the diminishing spray at the lower end of the casting with the lengthening of time.

The third pair of rails 42 enable a mold supporting unit that requires repair or replacement to be sidetracked to a working and servicing area along these rails at a place safely removed from the casting area and without interrupting the casting cycle.

As previously stated, the apparatus may comprise just one traclcway, as provided by the rails 40, with the units A being moved back and forth to casting, cooling and stripping stations, but with less facility than where they can travel one direction only through a closed cycle. Such an arrangement is indicated in the diagram in H6. 8 where 75 designates an elevated track corresponding to the track provided by rails 40 in FIGS. 5 to 7. There is a pouring ladle indicated at 76 movable on a cross track 77, as previously described. The stripping station is indicated at 78, and the dummy blocks may also be inserted at any location at either side of the ladle. The mold 79 is, of course, under the ladle. The first casting supporting units A may be moved to the right of the mold, the next ones moved to the left beyond the stripping station, then the ones on the right would be ready for stripping, so they would be moved to the left and stripped, afier which they could be again brought to casting position, while the ones last used would be stripped.

FIG. 9 is a schematic diagram where the casting supporting units A as heretofore described are located at fixed intervals under a track along which a ladle car and mold unit together, designated generally as 91, is movable. Each mold is positioned over a hydraulic ram arrangement 92 as described in FIGS. 5 to 7 for facilitating the stripping of the completed casting as previously described.

Instead of the dummy block having its upper end interlocked with the casting, it is sometimes preferable to have a separate head on the dummy block as shown in FIG. 13 where the dummy block is much like that shown in FIG. 10. it has two parts 95 and 96 with springs and tie bolts as shown in FIG.

10. Part 95 has a top 97 that extends over part 96, and it has a dovetailed or undercut ridge 98 down the longitudinal central area. There is a divided head comprised of two similar parts 99 and 100. The two parts together provide a dovetailed recess on the underside of the head that is interlocked with the ridge 98. The two parts of the head are releasably held together by tie-bolts and nuts 101. In the top of the head is a recess 102, the walls of which are undercut so that the recess is of dovetailed section. Around the periphery of the head there is a ledge 103 into which an asbestos rope or strand 104 is set. This may be done when the dummy block is prepared for use, so that the asbestos seal is already in place when the block is raised into the mold, avoiding the need, as at present to tamp asbestos around the dummy block after it is in the mold, as is common with conventional continuous casting. The molten metal when it enters the mold will tend to flatten the rope to provide the required seal for starting the casting. When the casting is finished, the head can be unbolted to remove the two parts from the casting.

A further modification is shown in FIG. where the dummy block 106, also formed in two parts as in FIGS. 10 and 13, has a wedgelike ridge 107 along the center of the top. The head is comprised of two separate blocks 108 and 109, one being at each side of the wedge. The two blocks are secured in position by tie-bolts with nuts at 1 10, the bolts passing through both blocks and the wedge. Each of the blocks 108 and 109 has a projecting rib 111 along the top with a laterally extending flange 112 thereon. The two parts and the ends of the wedge have a peripheral shoulder 113 for the asbestos rope seal 1 14.

This is a particularly useful arrangement for very large castings because of the surfaces that conduct heat away from the metal that first contacts the head so that solidification of the molten metal with the interlocking parts of the head occurs rapidly, and strength is quickly acquired sufficient to start pulling the casting down from its mold. The dummy block and head are released by removing the bolts 110 and dropping the dummy block from between the two head-forming sections, which then have clearance between them to enable them to be removed.

it is also contemplated that instead of hydraulic rams 71 being arranged to push upwardly on the casting, hydraulic rams may be used to lower or raise the supporting units themselves.

1 claim:

1. Slab casting apparatus for the casting of successive individually cast slabs comprising:

a. an elevated open-ended mold means of the type used for continuous casting,

b. a plurality of casting supporting and cooling units of the vertical-type designed to receive and support the incipiently formed casting as it emerges from the mold and confine it against deforming under hydrostating pressure of molten metal inside the casting, each support being of a length corresponding to the maximum length of the slab which the apparatus is designed to produce,

c. the mold and the said supporting units being supported for relative movement whereby a predetermined length of incipiently formed casting may be successively run into each casting supporting unit and retained for cooling, and

. a pouring ladle for supplying molten metal to the mold,

e. each supporting unit being arranged to slidably receive and frictionally hold a dummy block therein, and a plurality of dummy blocks each of which is slidable in and arranged to be held entirely by friction in the supporting units, said supporting units including means to eflect the movement of the dummy blocks and a casting emerging from the mold progressively from the top of the support throughout its length to the bottom of said support.

2. Slab casting apparatus as defined in claim 1 in which the pouring ladle is supported for movement relative to the mold and the casting supporting unit, between a position over the mold and a position at one side thereof, the ladle having a valved discharge opening in the bottom thereof for the intermittent discharge of molten metal from the ladle directly into the mold when the ladle is positioned above the mold.

3. Slab casting apparatus as defined in claim 1 wherein there is an elevated track above which the mold and pouring ladle are positioned, each casting supporting unit being carried on and suspended from a carriage movable along the said track into and out of position under the mold.

4. Slab casting apparatus as defined in claim 3 in which there is a second elevated track parallel with said first track, and means at one end of both tracks for transferring a carriage with its suspended casting supporting unit from the first track to the second and means at the other end of both tracks for transferring a carriage with its suspended mold-supporting unit from the second track to the first.

5. Slab casting apparatus as defined in claim 1 in which each casting supporting unit comprises a wheeled carriage, a pair of confronting spaced vertically elongated panels supported in the carriage for relative vertical movement, means on the carriage for simultaneously reciprocating the panels up and down with one moving up as the other moves down, a track along which the wheeled carriages are movable in succession, the mold being positioned above the track so that the wheeled frames and the panels supported therein may be moved into position under the mold and then removed from said position.

6. Casting apparatus as defined in claim 5 in which there is a casting stripping station along the track at one side of the mold, and means at the stripping station below said units for exerting an upward pressure against the casting in the unit to assist in the removal of a casting from the supporting unit.

7. Casting apparatus as defined in claim 9 wherein there is means at the stripping station onto which a dummy block at the bottom of the casting may be received and supported when it is detached from the casting and the casting is to be removed from the supporting unit.

8. Slab casting apparatus for the successive casting of individually cast slabs comprising:

a. a track elevated above ground level,

b. an open-ended mold of the type used in continuous casting located above the track,

c. a plurality of separate carriages movable along said track beneath the mold,

d. a cast-supporting unit carried by and suspended from each carriage arranged to be moved by its carriage along said track from a position in advance of said mold to a position under said mold and then to a position at the other side of the mold from the first position, said supporting units terminating at their lower ends above ground level and defining substantially the total length of any slab which may be cast in said apparatus, each such supporting unit being comprised of two confronting sections arranged to receive and progressively lower the casting being formed to the lower end of the supporting unit, and

e. separate individual dummy blocks arranged to be received in and held in place at the bottom of the mold entirely by the supporting unit at the beginning of the casting operation and moved down by operation of the supporting means with an attached casting as the casting operation proceeds.

9. Slab casting apparatus as defined in claim 8 wherein there is a spray zone of progressively diminishing height from the bottom upwardly toward the level of the track along each side of the path of travel of carriages with their suspended casting supports and in which cooling water is directed against the suspended casting supports as they move through said zone toward the direction of minimum height of said zone.

10. Slab casting apparatus as defined in claim 9 wherein the wide dimension of the slab and its support are parallel with the direction of travel of the supports through the spray zone.

11. Slab casting apparatus as defined in claim 8 wherein each supporting unit has water-cooled spray elements thereon arranged at closely spaced intervals on the support throughout substantially its entire height, and means for valving the water to said spray elements to effect a downwardly decreasing flow of water to said elements to compensate for the longer period of time the lower end of a cast slab in the support is exposed to the water-cooling spray from said elements as compared to the upper end of the casting.

12. Slab casting apparatus comprising:

a. an open-ended mold means of the type used for continuous casting,

b. a plurality of casting supporting and cooling units of the type designed to receive and support the incipiently formed casting as it emerges from the mold and confine it against deforming under hydrostatic pressure of molten metal inside the casting, each casting supporting unit comprising means for imparting longitudinal movement to the casting as it emerges from the mold,

c. the mold and the said supporting units being supported for relative movement whereby a predetermined length of incipiently formed casting may be successively run into i9. each casting supporting unit and retained for cooling,

d. a pouring ladle for supplying molten metal to the mold,

and

e. separate individual dummy blocks arranged to be received in and held in place at the bottom of the mold entirely by the supmrting unit at the beginning of the casting operation and moved down by operation of the supporting means with an attached casting as the casting operation proceeds.

13. Casting apparatus as defined in claim 12 wherein there is a cooling station laterally removed from the path in which the casting emerges from the mold, and there are means at the cooling station for accelerating the cooling of the castings while their supports are positioned in said station.

14. Casting apparatus as defined in claim 13 wherein said means for accelerating the cooling comprises water sprays arranged to project water against opposite faces of said supports.

* i i i t 

1. Slab casting apparatus for the casting of successive individually cast slabs comprising: a. an elevated open-ended mold means of the type used for continuous casting, b. a plurality of casting supporting and cooling units of the vertical-type designed to receive and support the incipiently formed casting as it emerges from the mold and confine it against deforming under hydrostating pressure of molten metal inside the casting, each support being of a length corresponding to the maximum length of the slab which the apparatus is designed to produce, c. the mold and the said supporting units being supported for relative movement whereby a predetermined length of incipiently formed casting may be successively run into each casting supporting unit and retained for cooling, and d. a pouring ladle for supplying molten metal to the mold, e. each supporting unit being arranged to slidably receive and frictionally hold a dummy block therein, and a plurality of dummy blocks each of which is slidable in and arranged to be held entirely by friction in the supporting units, said supporting units including means to effect the movement of the dummy blocks and a casting emerging from the mold progressively from the top of the support throughout its length to the bottom of said support.
 2. Slab casting apparatus as defined in claim 1 in which the pouring ladle is supported for movement relative to the mold and the casting supporting unit, between a position over the mold and a position at one side thereof, the ladle having a valved discharge opening in the bottom thereof for the intermittent discharge of molten metal from the ladle directly into the mold when the ladle is positioned above the mold.
 3. Slab casting apparatus as defined in claim 1 wherein there is an elevated track above which the mold and pouring ladle are positioned, each casting supporting unit being carried on and suspended from a carriage movable along the said track into and out of position under the mold.
 4. Slab casting apparatus as defined in claim 3 in which there is a second elevated track parallel with said first track, and means at one end of both tracks for transferring a carriage with its suspended casting supporting unit from the first track to the second and means at the other end of both tracks for transferring a carriage with its suspended mold-supporting unit fRom the second track to the first.
 5. Slab casting apparatus as defined in claim 1 in which each casting supporting unit comprises a wheeled carriage, a pair of confronting spaced vertically elongated panels supported in the carriage for relative vertical movement, means on the carriage for simultaneously reciprocating the panels up and down with one moving up as the other moves down, a track along which the wheeled carriages are movable in succession, the mold being positioned above the track so that the wheeled frames and the panels supported therein may be moved into position under the mold and then removed from said position.
 6. Casting apparatus as defined in claim 5 in which there is a casting stripping station along the track at one side of the mold, and means at the stripping station below said units for exerting an upward pressure against the casting in the unit to assist in the removal of a casting from the supporting unit.
 7. Casting apparatus as defined in claim 9 wherein there is means at the stripping station onto which a dummy block at the bottom of the casting may be received and supported when it is detached from the casting and the casting is to be removed from the supporting unit.
 8. Slab casting apparatus for the successive casting of individually cast slabs comprising: a. a track elevated above ground level, b. an open-ended mold of the type used in continuous casting located above the track, c. a plurality of separate carriages movable along said track beneath the mold, d. a cast-supporting unit carried by and suspended from each carriage arranged to be moved by its carriage along said track from a position in advance of said mold to a position under said mold and then to a position at the other side of the mold from the first position, said supporting units terminating at their lower ends above ground level and defining substantially the total length of any slab which may be cast in said apparatus, each such supporting unit being comprised of two confronting sections arranged to receive and progressively lower the casting being formed to the lower end of the supporting unit, and e. separate individual dummy blocks arranged to be received in and held in place at the bottom of the mold entirely by the supporting unit at the beginning of the casting operation and moved down by operation of the supporting means with an attached casting as the casting operation proceeds.
 9. Slab casting apparatus as defined in claim 8 wherein there is a spray zone of progressively diminishing height from the bottom upwardly toward the level of the track along each side of the path of travel of carriages with their suspended casting supports and in which cooling water is directed against the suspended casting supports as they move through said zone toward the direction of minimum height of said zone.
 10. Slab casting apparatus as defined in claim 9 wherein the wide dimension of the slab and its support are parallel with the direction of travel of the supports through the spray zone.
 11. Slab casting apparatus as defined in claim 8 wherein each supporting unit has water-cooled spray elements thereon arranged at closely spaced intervals on the support throughout substantially its entire height, and means for valving the water to said spray elements to effect a downwardly decreasing flow of water to said elements to compensate for the longer period of time the lower end of a cast slab in the support is exposed to the water-cooling spray from said elements as compared to the upper end of the casting.
 12. Slab casting apparatus comprising: a. an open-ended mold means of the type used for continuous casting, b. a plurality of casting supporting and cooling units of the type designed to receive and support the incipiently formed casting as it emerges from the mold and confine it against deforming under hydrostatic pressure of molten metal inside the casting, each casting supporting unit comprising means for imparting longitudinal movement to the casting as it emerges from the mold, c. the mold and the said supporting units being supported for relative movement whereby a predetermined length of incipiently formed casting may be successively run into each casting supporting unit and retained for cooling, d. a pouring ladle for supplying molten metal to the mold, and e. separate individual dummy blocks arranged to be received in and held in place at the bottom of the mold entirely by the supporting unit at the beginning of the casting operation and moved down by operation of the supporting means with an attached casting as the casting operation proceeds.
 13. Casting apparatus as defined in claim 12 wherein there is a cooling station laterally removed from the path in which the casting emerges from the mold, and there are means at the cooling station for accelerating the cooling of the castings while their supports are positioned in said station.
 14. Casting apparatus as defined in claim 13 wherein said means for accelerating the cooling comprises water sprays arranged to project water against opposite faces of said supports. 